I love my daughter, BUT!

My 3 yr old is really irritating me right now.  I need help trying to keep what's suppose to be a fun day, fun and relaxed in the midst of my daughter's irritating habits.  So I tell her  "Eat your breakfast because we are going to the water park".  It's indoors and they don't allow food.  She lets her breakfast sit and sit, claiming that she wasn't hungry.  So we walk down the 20 steps outside our house to get in our car...........once we are in the car she says "I want my snacks".  I'm like "no, those snacks are for while we are out at the water park".  Then I'm like "If you're hungry, go back inside and eat that french toast".  She says "Ok".  Back up the 20 steps and another 15 steps to get upstairs in our house so she can eat the breakfast I told her to eat earlier.  Now we are really off schedule.  Instead of going to the bank before our friends get here we have to wait until after they get here and I desperately have to get to the vitamin shop.  Which is kind of making us run late.  It's seems like you can never be on time with Preschoolers in tow.  You're either going to be early or your going to be late.  Well, that's been my experience.